全文获取类型
收费全文 | 1424篇 |
免费 | 75篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 19篇 |
综合类 | 37篇 |
化学工业 | 319篇 |
金属工艺 | 35篇 |
机械仪表 | 13篇 |
建筑科学 | 125篇 |
矿业工程 | 4篇 |
能源动力 | 44篇 |
轻工业 | 153篇 |
水利工程 | 8篇 |
无线电 | 63篇 |
一般工业技术 | 255篇 |
冶金工业 | 199篇 |
原子能技术 | 3篇 |
自动化技术 | 224篇 |
出版年
2023年 | 13篇 |
2022年 | 18篇 |
2021年 | 35篇 |
2020年 | 34篇 |
2019年 | 31篇 |
2018年 | 33篇 |
2017年 | 33篇 |
2016年 | 53篇 |
2015年 | 41篇 |
2014年 | 54篇 |
2013年 | 87篇 |
2012年 | 57篇 |
2011年 | 100篇 |
2010年 | 80篇 |
2009年 | 69篇 |
2008年 | 80篇 |
2007年 | 82篇 |
2006年 | 69篇 |
2005年 | 62篇 |
2004年 | 44篇 |
2003年 | 36篇 |
2002年 | 20篇 |
2001年 | 31篇 |
2000年 | 15篇 |
1999年 | 31篇 |
1998年 | 52篇 |
1997年 | 37篇 |
1996年 | 36篇 |
1995年 | 14篇 |
1994年 | 11篇 |
1993年 | 19篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 3篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1977年 | 9篇 |
1976年 | 6篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1966年 | 3篇 |
1965年 | 2篇 |
1964年 | 3篇 |
排序方式: 共有1501条查询结果,搜索用时 15 毫秒
1.
2.
3.
A system for person-independent classification of hand postures against complex backgrounds in video images is presented. The system employs elastic graph matching, which has already been successfully applied for object and face recognition. We use the bunch graph technique to model variance in hand posture appearance between different subjects and variance in backgrounds. Our system does not need a separate segmentation stage but closely integrates finding the object boundaries with posture classification. 相似文献
4.
Matthias Zobel Joachim Denzler Benno Heigl Elmar Nöth Dietrich Paulus Jochen Schmidt Georg Stemmer 《Machine Vision and Applications》2003,14(1):26-34
Abstract. This contribution introduces MOBSY, a fully integrated, autonomous mobile service robot system. It acts as an automatic dialogue-based
receptionist for visitors to our institute. MOBSY incorporates many techniques from different research areas into one working
stand-alone system. The techniques involved range from computer vision over speech understanding to classical robotics.
Along with the two main aspects of vision and speech, we also focus on the integration aspect, both on the methodological
and on the technical level. We describe the task and the techniques involved. Finally, we discuss the experiences that we
gained with MOBSY during a live performance at our institute. 相似文献
5.
It is well recognized that performance changes over time. However, the effect of these changes on overall assessments of performance is largely unknown. In a laboratory experiment, we examined the influence of salient Gestalt characteristics of a dynamic performance profile on supervisory ratings. We manipulated performance trend (flat, linear-improving, linear-deteriorating, U-shaped, and ∩-shaped), performance variation (small, large), and performance mean (negative, zero, positive) within subjects and display format (graphic, tabular) between subjects. Participants received and evaluated information about the weekly performance of different employees over a simulated 26-week period. Results showed strong main effects on performance ratings of both performance mean and performance trend, as well as interactions with display format. Theoretical and practical implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Awareness of the construction environment can be improved by automatic three-dimensional (3D) sensing and modeling of job sites in real time. Commercially available 3D modeling approaches based on range scanning techniques are capable of modeling static objects only, and thus cannot model dynamic objects in real time in an environment comprised of moving humans, equipment, and materials. Emerging prototype video range cameras offer an alternative by facilitating affordable, wide field of view, dynamic object tracking at frame rates better than 1?Hz (real time). This paper describes a methodology to model, detect, and track the position of static and moving objects in real time, based on data obtained from video range cameras. Experiments with this technology have produced results that indicate that video rate 3D data acquisition and analysis of construction environments can support effective modeling, detection, and tracking of project resources. This approach to job site awareness has inherent value and broad application. In combination with effective management practices and other sensing techniques, this technology has the potential to significantly improve safety on construction job sites. 相似文献
7.
We determined the nucleotide sequence of the SH gene its flanking regions over a range of 380 nucleotides for three distinct mumps virus (MUV) isolates. Two isolates from the 1992 mumps epidemic in Western Switzerland and one MUV isolated in 1995 in the same geographic area have been analyzed and compared to 16 recently published SH nucleotide sequences and their presumed amino acid sequences. The nucleotide sequences from the 1992 MUV isolates were identical and closely related to two MUV strains from Eastern Switzerland and strains from the U.K. The MUV isolated in 1995 is clearly different from all other strains. 相似文献
8.
9.
10.
First, annual cost of electronic filing of medical images were calculated and compared with that of film storage in two hospitals under different conditions. Storage of medical images using a pixel size of 100 microns x 100 microns and 2-byte depth on the 130 mm, 650 MB magneto-optical disks costs with four times as much as the cost for film storage. However, 175 microns x 175 microns 12 bits combined with implementation of lossless compression would reduce the cost to a level equal to that for films storage. Doubled or tripled densities of MOD will improve the cost ever further. Second, the effectiveness of Hospital Information System/Radiological Information System (HIS/RIS) was evaluated. Examination time, film delivery time and the total turn-around time was markedly shortened by more than 23 hours on average. Our measurement method employing IC cards in pre-post HIS/RIS/PACS procedures is generally applicable to other hospitals. Third, to determine the optimal method of maximizing the efficacy of diagnostic imaging, 260 questionnaires were sent to the staff of 13 university hospitals. Every situation was described by both a radiologist and the physician who ordered the examination and received the reports and images. The level of technical efficacy and diagnostic accuracy of radiology strongly influenced the diagnostic thought processes of the physician. 相似文献